Cooling system for a casting machine (40), in particular for the directional cooling of permanent molds in an injection molding machine, said system comprising: a plurality of cooling fingers (1) in contact with a mold (42) of said molding machine, a cooling machine (30) capable of alternately injecting into said cooling fingers a heat transfer fluid and a pressurized gas in order to remove said heat transfer fluid from said cooling finger, characterized in that said cooling system comprises a plurality of elements (101-108) referred to as flow measuring elements, each flow measuring element being capable of measuring a parameter representative of the flow rate of heat transfer fluid injected into a respective cooling finger.